I was a little premature yesterday in stating that the problem was resolved as I am still getting the start page telling me that I am not on the latest version and that I should upgrade. This is with Firefox 9. I can only assume that johndrew's suggestion that the installation may be corrupt is the case, but, as I said yesterday, how can I tell and what can I do about it?

I had also overlooked the fact that, as happened initially with previous versions of Firefox, Kaspersky Pure Password Manager does not work with Firefox 9 so I am minded to revert to Firefox 8 until Kaspersky can issue a patch.